Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 25
Filtrar
1.
iScience ; 27(6): 109952, 2024 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-38812537

RESUMEN

The sun and outer space are two crucial renewable thermodynamic resources that work together to maintain the delicate energy balance of our planet. The challenge lies in harvesting both resources synergistically and converting them into high-quality electricity. Here, we introduce a photovoltaic thermoelectric radiative cooling (PV-TE-RC) system. This system uses the full spectrum of the sun and the atmospheric window to generate electricity and achieve high-quality collaborative utilization of solar energy and space energy. Outdoor experiments have demonstrated the system's capacity to operate efficiently around the clock. Notably, during the peak solar concentration, the thermoelectric generator (TEG) and the system achieved power outputs of 870 mW/m2 and 85.87 W/m2, respectively. We have further developed a three-dimensional transient coupled simulation model, which can accurately predict its operational limits. Therefore, this study provides practical insights and recommendations for large-scale and efficient collaborative power generation using these two thermodynamic resources.

2.
World J Gastrointest Surg ; 15(6): 1240-1246, 2023 Jun 27.
Artículo en Inglés | MEDLINE | ID: mdl-37405102

RESUMEN

BACKGROUND: Fishbone migration from the esophagus to the neck is relatively uncommon in clinical practice. Several complications secondary to esophageal perforation after ingestion of a fishbone have been described in the literature. Typically, a fishbone is detected and diagnosed by imaging examination and is usually removed by a neck incision. CASE SUMMARY: Herein, we report a case of a 76-year-old patient with a fishbone in the neck that had migrated from the esophagus and that was in close proximity to the common carotid artery, and the patient experienced dysphagia. An endoscopically-guided neck incision was made over the insertion point in the esophagus, but the surgery failed due to having a blurred image at the insertion site during the operation. After injection of normal saline laterally to the fishbone in the neck under ultrasound guidance, the purulent fluid outflowed to the piriform recess along the sinus tract. With endoscopic guidance, the position of the fish bone was precisely located along the direction of liquid outflow, the sinus tract was separated, and the fish bone was removed. To the best of our knowledge, this is the first case report describing bedside ultrasound-guided water injection positioning combined with endoscopy in the treatment of a cervical esophageal perforation with an abscess. CONCLUSION: In conclusion, the fishbone could be located by the water injection method under the guidance of ultrasound and could be accurately located along the outflow direction of the purulent fluid of the sinus by the endoscope and was removed by incising the sinus. This method can be a nonoperative treatment option for foreign body-induced esophageal perforation.

3.
Eur Radiol ; 33(7): 4895-4904, 2023 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-36840765

RESUMEN

OBJECTIVES: To compare the performances of lung ultrasonography (LUS) versus chest CT for assessing peripheric pulmonary lesions in hemorrhagic fever with renal syndrome (HFRS). METHODS: Paired LUS and chest CT scan were prospectively performed and compared when in diagnosing five pathologies including region with alveolar-interstitial pattern (RAIP), alveolar-interstitial syndrome (AIS), lung consolidation, pleural effusion (PE), and pericardial effusion, in each patient with HFRS. RESULTS: Forty-four patients (aged 39.9 ± 15.0 years, 35 males) were included, from which 68 paired LUS and chest CT imaging data of 816 lung regions were obtained and analyzed. Compared with chest CT, LUS showed high sensitivity (92.19-100%) and negative predictive value (95.9-100%), but relatively low specificity (39.47-97.21%) and positive predictive value (37.5-76.47%) for diagnosing the above pathologies. McNemer's test showed LUS detected more positive findings than chest CT (all p ≤ 0.002). There was a strong correlation between LUS and chest CT scores (rs = 0.7141, p < 0.0001) and both scores correlated with the disease severity, hospital days, and partial laboratory profiles in HFRS patients. CONCLUSIONS: LUS was comparable with chest CT for diagnosing peripheric pulmonary lesions and clinical assessment in patients with HFRS. Given the high sensitivity and negative predictive value compared with chest CT, LUS can be used as an excellent rule-out tool in HFRS, while its use in rule-in still requires more evidence. Considering the obvious advantages of LUS being a bedside, less expansive, and non-radiating exam, future multi-center randomized LUS versus chest CT studies may help to guide the preferred method. KEY POINTS: • LUS could detect more positive findings than chest CT in assessing peripheric pulmonary lesions in patients with hemorrhagic fever with renal syndrome (HFRS). • Compared with chest CT, LUS showed high sensitivity but relatively low specificity when diagnosing the peripheric pulmonary lesions caused by HFRS. • Both LUS and chest CT scores correlated with the disease severity, hospital days, and partial laboratory profiles in HFRS.


Asunto(s)
Fiebre Hemorrágica con Síndrome Renal , Masculino , Humanos , Fiebre Hemorrágica con Síndrome Renal/diagnóstico por imagen , Estudios Prospectivos , Pulmón/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Ultrasonografía/métodos
4.
Chem Sci ; 12(43): 14432-14440, 2021 Nov 10.
Artículo en Inglés | MEDLINE | ID: mdl-34880994

RESUMEN

Recently, stretchable electrochemical sensors have stood out as a powerful tool for the detection of soft cells and tissues, since they could perfectly comply with the deformation of living organisms and synchronously monitor mechanically evoked biomolecule release. However, existing strategies for the fabrication of stretchable electrochemical sensors still face with huge challenges due to scarce electrode materials, demanding processing techniques and great complexity in further functionalization. Herein, we report a novel and facile strategy for one-step preparation of stretchable electrochemical biosensors by doping ionic liquid and catalyst into a conductive polymer (poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate), PEDOT:PSS). Bis(trifluoromethane) sulfonimide lithium salt as a small-molecule plasticizer can significantly improve the stretchability and conductivity of the PEDOT:PSS film, and cobalt phthalocyanine as an electrocatalyst endows the film with excellent electrochemical sensing performance. Moreover, the functionalized PEDOT:PSS retained good cell biocompatibility with two extra dopants. These satisfactory properties allowed the real-time monitoring of stretch-induced transient hydrogen peroxide release from cells. This work presents a versatile strategy to fabricate conductive polymer-based stretchable electrodes with easy processing and excellent performance, which benefits the in-depth exploration of sophisticated life activities by electrochemical sensing.

5.
Infect Genet Evol ; 89: 104706, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33418145

RESUMEN

To assess the heterogeneity of HBV reverse transcriptase (RT) quasispecies during 10 years of antiviral therapy and their association with antiviral efficacy. Nineteen patients with chronic hepatitis B (CHB) infection receiving nucleos(t)ide analogues (NAs) were enrolled. Based on the antiviral efficacy after 1 year of treatment, 5 patients were grouped into an early virologic response (EVR) group, while 8 patients were grouped into a late virologic response (LVR) group. Furthermore, 6 CHB patients that had undergone antiviral treatment for 10 years were grouped into a virologic breakthrough (VBT) group. The HBV RT from each patient were amplified, cloned, and sequenced. The complexity of the RT gene in the EVR group was significantly higher than that in the LVR (P = 0.0393) and VBT groups (P = 0.0141). Phylogenetic tree analysis showed that the average branch length of the EVR and LVR groups were significantly greater than that of VBT group (P < 0.001). The complexity (at the nucleotide level) of the RT quasispecies was negatively correlated with the corresponding HBV DNA load (P = 0.0163) at one year post-antiviral treatment. Moreover, both the LVR and VBT groups accumulated more deleterious mutations than the EVR group. After 1 year of NAs treatment, the increased HBV quasispecies complexity and evolutionary topologies, coupled with less deleterious mutations, are likely associated with a favorable efficacy during long-term antiviral treatment.


Asunto(s)
Antivirales/farmacología , Heterogeneidad Genética , Virus de la Hepatitis B/enzimología , ADN Polimerasa Dirigida por ARN/genética , Adolescente , Adulto , Alanina Transaminasa/sangre , ADN Viral/genética , Femenino , Virus de la Hepatitis B/efectos de los fármacos , Virus de la Hepatitis B/genética , Humanos , Masculino , Adulto Joven
6.
Chem Sci ; 12(47): 15771, 2021 Dec 08.
Artículo en Inglés | MEDLINE | ID: mdl-35003610

RESUMEN

[This corrects the article DOI: 10.1039/D1SC04138J.].

7.
Kaohsiung J Med Sci ; 36(6): 450-459, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-31913555

RESUMEN

China lacks data demonstrating associations of cervical neoplastic lesions with CD4 T-lymphocyte (CD4 cell) counts and antiretroviral therapy (ART) among HIV-infected women, suggesting relevant investigations are needed. A total of 545 HIV-infected women were enrolled in Yunnan, China, between 2011 and 2013. CD4 cell counts and ART were measured via medical records and cervical neoplastic lesions were measured by professional pathologists. Multivariable logistic models, which treated cervical intraepithelial neoplasia (CIN) 1+ and CIN2+ as outcomes, calculated adjusted odds ratio (aOR) of CD4 cell counts and ART. Subgroup analysis treating CIN1+ as the outcome was conducted by HIV infection duration (<4 vs ≥4 years), ethnicity (Han vs non-Han), and study site (Mangshi vs Kunming). The prevalence of CIN1+ and CIN2+ was 17.4% and 7.3%, respectively. Overall, 243 (44.6%) women had CD4 cell counts ≥500 cell/µL, 187 (34.3%) used ART for less than 2 years, and 236 (43.3%) used ART for at least 2 years. We found inverse associations of CIN1+ with CD4 cell counts (≥500 compared to <500 cells/µL: aOR = 0.46, 95% CI = 0.27-0.79) and ART use (<2 years: aOR = 0.43, 95% CI = 0.21-0.87; ≥2 years: aOR = 0.54, 95% CI = 0.27-1.10). Point estimates did not change substantially for CIN2+ but aORs of ART became nonsignificant. No significant interaction was observed for HIV infection duration. We found significant interaction between CD4 cell counts and ethnicity and study site in relation to CIN1+. Our study suggests potential protective effects of high CD4 cell counts against cervical neoplastic lesions among HIV-infected women, whereas associations of ART are less consistent.


Asunto(s)
Fármacos Anti-VIH/uso terapéutico , Linfocitos T CD4-Positivos/patología , Infecciones por VIH/patología , Displasia del Cuello del Útero/patología , Neoplasias del Cuello Uterino/patología , Adulto , Anciano , Terapia Antirretroviral Altamente Activa , Recuento de Linfocito CD4 , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/virología , Cuello del Útero/inmunología , Cuello del Útero/patología , Cuello del Útero/virología , China/epidemiología , Etnicidad , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/etnología , Infecciones por VIH/virología , Humanos , Modelos Logísticos , Persona de Mediana Edad , Oportunidad Relativa , Prevalencia , Índice de Severidad de la Enfermedad , Neoplasias del Cuello Uterino/tratamiento farmacológico , Neoplasias del Cuello Uterino/etnología , Neoplasias del Cuello Uterino/virología , Displasia del Cuello del Útero/tratamiento farmacológico , Displasia del Cuello del Útero/etnología , Displasia del Cuello del Útero/virología
8.
Tree Physiol ; 39(10): 1783-1791, 2019 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-31209479

RESUMEN

Xylem vessels are used by most angiosperm plants for long-distance water and nutrient transport. Vessel length is one of the key functional traits determining plant water-transport efficiency. Additionally, determination of maximum vessel length is necessary for correct sample collection and measurements in hydraulic studies to avoid open-vessel and cutting-under-tension artifacts. Air injection and silicone injection (BLUESIL RTV141A and B mixtures) are two widely used methods for maximum vessel length determination. However, the validity of both methods needs to be carefully tested for species with different vessel lengths. In this study, we tested the air-injection and silicone-injection methods using eight species with different vessel lengths: short (<0.5 m), medium (0.5-1 m) and long (>1 m). We employed a novel approach using RTV141A injection without the RTV141B hardener as a reference method because RTV141A cannot penetrate inter-vessel pit membranes and is not prone to hardening/solidification effects during the injection process. The results revealed that the silicone-injection method substantially underestimated the maximum vessel length of all eight species. However, the air-injection method tended to overestimate the maximum vessel length in five out of eight species. The ratio of underestimation of the silicone-injection method was higher for species with longer vessels, but the overestimation of the air-injection method was independent of the vessel length. Moreover, air injection with different pressures-ranging from 40 to 300 kPa-resulted in comparable results. We conclude that the conventional silicone-injection method can underestimate the vessel length, whereas the air-injection method can overestimate the maximum vessel length, particularly for long-vessel led species. We recommend RTV141A-only injection for determining the maximum vessel length, and it can also be used to validate the use of the air-injection and conventional silicone-injection methods for a given species.


Asunto(s)
Artefactos , Magnoliopsida , Siliconas , Agua , Xilema
9.
Medicine (Baltimore) ; 98(17): e15388, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31027132

RESUMEN

RATIONALE: Chondrosarcoma is a malignant mesenchymal tumor originating from cartilage. The pelvis, ribs, femur, and humerus are the most frequently affected sites, and scapula involvement is relatively rare. The aim of the present study was to report a case of chondrosarcoma in the scapula. PATIENT CONCERNS: A 42-year-old woman presented with a 3-month history of a painful mass in the right scapula. DIAGNOSES AND INTERVENTION: The patient underwent tumor resection. The post-operative pathological diagnosis was scapula chondrosarcoma. OUTCOMES: Following resection, the patient continued to receive routine follow-up care. There was no recurrence or tumor metastasis at a follow-up of 5 years. CONCLUSIONS: Surgery remains the primary therapy for chondrosarcoma. One of the greatest challenges in the management of chondrosarcoma is to accurately assess tumor grade before surgical intervention. Chemotherapy and radiotherapy have been applied without success. Chemo- and radioresistance have been examined beyond classic phenotypic properties to identify more efficient therapeutic strategies. Therefore, development of future novel therapies is contingent upon elucidating the molecular mechanisms of chondrosarcoma.


Asunto(s)
Neoplasias Óseas/diagnóstico , Condrosarcoma/diagnóstico , Escápula , Adulto , Neoplasias Óseas/patología , Neoplasias Óseas/cirugía , Condrosarcoma/patología , Condrosarcoma/cirugía , Diagnóstico Diferencial , Femenino , Humanos , Escápula/patología , Escápula/cirugía
10.
RSC Adv ; 9(40): 23229-23240, 2019 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-35514511

RESUMEN

The effect of the slip lengths of both continuous and dispersed phases on droplet formation in microfluidic T-junctions is investigated by a volume of fluid method. Results reveal that, in a dripping regime, the droplet size is mainly influenced by the slip length of the continuous phase and increases with it. In a squeezing regime, the droplet size decreases with the slip lengths of both phases. The effects of the slip lengths of both phases on droplet generation are systematically discussed and summarized. The elongation rate of the thread can be decreased with an increase of slip lengths in both dripping and squeezing regimes, which is beneficial to improve droplet monodispersity. The monodispersity of droplets can deteriorate when the slip length of either phase is small and can be improved by increasing the slip length of the other phase.

11.
ACS Appl Mater Interfaces ; 10(26): 22278-22290, 2018 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-29901386

RESUMEN

The composites based on graphitic carbon and transitional metal oxides are regarded as one of the most promising electrochemical materials owing to the synergistic combination of the advantages of both superior electrical conductivity and high pseudocapacitance. In this work, a simple one-pot template-free strategy for the preparation of three-dimensional hierarchical porous nitrogen-doped carbon framework in situ armored NiO nanograins (NCF/NiO) by an ammonia-induced method assisted by the pyrolysis of a decomposable salt is reported. Due to such unique architecture and homogeneously dispersed nanoparticles, the as-prepared NCF/NiO-2 hybrid exhibits a large specific surface area (412.3 m2 g-1), a high specific capacitance (1074 F g-1 at 1 A g-1), good rate capability (820 F g-1 at 20 A g-1), and outstanding cycling performance (almost no decay after 5000 cycles). Moreover, the solid-state asymmetric supercapacitor, assembled with NCF/NiO-2 and NCS electrodes, can achieve a high cell potential of 1.6 V and deliver a superior specific capacitance of 113 F g-1 at 1 A g-1 with a maximum energy density of 40.18 W h kg-1 at a power density of 800 W kg-1, consequently, giving rise to stable cycling performance (94.3% retention over 5000 cycles). The prepared devices are shown to power 20 green light-emitting diodes efficiently. These encouraging results open up a wide horizon for developing novel carbon-supported metal oxide electrode materials for high rate energy conversion and storage devices.

12.
ACS Appl Mater Interfaces ; 10(10): 8393-8398, 2018 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-29488378

RESUMEN

High-quality CH3NH3PbI3-xCl x films have attracted research interests in photoelectric devices because of their improved carrier diffusion length and charge mobility. Herein, a solvent-assisted thermal-pressure strategy is developed to promote the secondary growth of perovskite grains in the films. Highly oriented perovskite films are then obtained with large-sized grains (5-10 µm). As a consequence, the photodetectors based on the high-quality CH3NH3PbI3- xCl x films exhibit enhanced ophtoelectrical performance, including high on/off ratio (>2.1 × 104), fast response time (54/63 µs), and high detectivity (∼1.3 × 1012). This work suggests an effective approach for high-quality perovskite films, which will be promising candidates for other high-efficiency photoelectric devices.

13.
Nano Lett ; 18(2): 1213-1220, 2018 02 14.
Artículo en Inglés | MEDLINE | ID: mdl-29389136

RESUMEN

High-quality organic-inorganic hybrid perovskite films are crucial for excellent performance of photoelectric devices. Herein, we demonstrate a pressure-assisted space-confined solvent-engineering strategy to grow highly oriented, pinhole-free thin films of CH3NH3PbI3 with large-scale crystalline grains, high smoothness, and crystalline fusion on grain boundaries. These single-crystalline grains vertically span the entire film thickness. Such a film feature dramatically reduces recombination loss and then improves the transport property of charge carriers in the films. Consequently, the photodetector devices, based on the high-quality CH3NH3PbI3 films, exhibit high photocurrent (105 µA under 671 nm laser with a power density of 20.6 mW/cm2 at 10 V), good stability, and, especially, an ultrahigh on/off ratio (Ilight/Idark > 2.2 × 104 under an incident light of 20.6 mW/cm2). These excellent performances indicate that the high-quality films will be potential candidates in other CH3NH3PbI3-based photoelectric devices.

14.
Medicine (Baltimore) ; 96(48): e8962, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-29310397

RESUMEN

RATIONALE: Desmoplastic fibroma (DF) is a rare, locally invasive but benign bone tumor. It represents one of the rarest bone diseases, with an incidence of only 0.11% of all primary bone tumors. PATIENT CONCERNS: Herein, a case of massive and unusual DF, with simultaneous involvement of ilium and ischium, is described. A 29-year-old man suffered minor pain in his right hip for 2 years. It worsened after sudden movements, which prevented him from walking normally. Physical examination showed a limitation when the right hip was flexed and a percussion pain on the hip region. A medical imaging examination showed that the right ilium and ischium had a massive bone lesion. The top of acetabular had very little bone left and a fracture was likely at any time. No prominent body weight loss was noted, because there was no extensive invasion to the adjacent soft tissue. DIAGNOSES: DF of the Ilium and Ischium. INTERVENTIONS: The patient underwent a surgery involving curettage and grafting to maintain the stability of the pelvis. OUTCOMES: The definitive pathological diagnosis was DF, without evidence of malignancy. The postoperative recovery course at 3-month follow-up was uneventful. LESSONS: To the authors' knowledge, such a massive DF involving both ilium and ischium has been rarely reported. Young patients require appropriate and timely treatment modalities.


Asunto(s)
Neoplasias Óseas/cirugía , Fibroma Desmoplásico/cirugía , Ilion/cirugía , Isquion/cirugía , Adulto , Neoplasias Óseas/diagnóstico por imagen , Neoplasias Óseas/patología , Legrado , Fibroma Desmoplásico/diagnóstico por imagen , Fibroma Desmoplásico/patología , Humanos , Ilion/diagnóstico por imagen , Ilion/patología , Isquion/diagnóstico por imagen , Isquion/patología , Masculino , Trasplante de Tejidos
15.
ACS Nano ; 10(6): 6201-10, 2016 06 28.
Artículo en Inglés | MEDLINE | ID: mdl-27299807

RESUMEN

Isolation of single circulating tumor cells (CTCs) from patients is a very challenging technique that may promote the process of individualized antitumor therapies. However, there exist few systems capable of highly efficient capture and release of single CTCs with high viability for downstream analysis and culture. Herein, we designed a near-infrared (NIR) light-responsive substrate for highly efficient immunocapture and biocompatible site-release of CTCs by a combination of the photothermal effect of gold nanorods (GNRs) and a thermoresponsive hydrogel. The substrate was fabricated by imprinting target cancer cells on a GNR-pre-embedded gelatin hydrogel. Micro/nanostructures generated by cell imprinting produce artificial receptors for cancer cells to improve capture efficiency. Temperature-responsive gelatin dissolves rapidly at 37 °C; this allows bulk recovery of captured CTCs at physiological temperature or site-specific release of single CTCs by NIR-mediated photothermal activation of embedded GNRs. Furthermore, the system has been applied to capture, individually release, and genetically analyze CTCs from the whole blood of cancer patients. The multifunctional NIR-responsive platform demonstrates excellent performance in capture and site-release of CTCs with high viability, which provides a robust and versatile means toward individualized antitumor therapies and also shows promising potential for dynamically manipulating cell-substrate interactions in vitro.


Asunto(s)
Hidrogeles , Rayos Infrarrojos , Nanotubos , Células Neoplásicas Circulantes , Línea Celular Tumoral , Oro , Humanos
16.
Anal Chem ; 88(13): 6773-80, 2016 07 05.
Artículo en Inglés | MEDLINE | ID: mdl-27291464

RESUMEN

Effective isolation of circulating tumor cells (CTCs) has great significance for cancer research but is highly challenged. Here, we developed a microchip embedded with a three-dimensional (3D) PDMS scaffold by a quadratic-sacrificing template method for high-efficiency capture of CTCs. The microchip was gifted with a 3D interconnected macroporous structure, strong toughness, and excellent flexibility and transparency, enabling fast isolation and convenient observation of CTCs. Especially, 3D scaffold chip perfectly integrates the two main strategies currently used for enhancement of cell capture efficiency. Spatially distributed 3D scaffold compels cells undergoing chaotic or vortex migration in the channel, and the spatially distributed nanorough skeleton offers ample binding sites, which synergistically and significantly improve CTCs capture efficiency. Our results showed that 1-118 CTCs/mL were identified from 14 cancer patients' blood and 5 out of these cancer patients showed 1-14 CTC clusters/mL. This work demonstrates for the first time the development of microchip with transparent interconnected 3D scaffold for isolation of CTCs and CTC clusters, which may promote in-depth analysis of CTCs.


Asunto(s)
Dimetilpolisiloxanos/química , Técnicas Analíticas Microfluídicas/métodos , Células Neoplásicas Circulantes/metabolismo , Anticuerpos Inmovilizados/química , Anticuerpos Inmovilizados/inmunología , Molécula de Adhesión Celular Epitelial/inmunología , Molécula de Adhesión Celular Epitelial/metabolismo , Humanos , Células MCF-7 , Análisis por Micromatrices , Técnicas Analíticas Microfluídicas/instrumentación , Microscopía Fluorescente , Neoplasias/sangre , Neoplasias/patología , Células Neoplásicas Circulantes/patología , Porosidad
18.
Anal Chem ; 88(2): 1378-84, 2016 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-26707930

RESUMEN

DNA methylation (5-methylcytosine, 5-mC) is the best characterized epigenetic mark that has regulatory roles in diverse biological processes. Recent investigation of RNA modifications also raises the possible functions of RNA adenine and cytosine methylations on gene regulation in the form of "RNA epigenetics." Previous studies demonstrated global DNA hypomethylation in tumor tissues compared to healthy controls. However, DNA and RNA methylation in circulating tumor cells (CTCs) that are derived from tumors are still a mystery due to the lack of proper analytical methods. In this respect, here we established an effective CTCs capture system conjugated with a combined strategy of sample preparation for the captured CTCs lysis, nucleic acids digestion, and nucleosides extraction in one tube. The resulting nucleosides were then further analyzed by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS). With the developed method, we are able to detect DNA and RNA methylation (5-methyl-2'-deoxycytidine, 5-methylcytidine, and N(6)-methyladenosine) in a single cell. We then further successfully determined DNA and RNA methylation in CTCs from lung cancer patients. Our results demonstrated, for the first time, a significant decrease of DNA methylation (5-methyl-2'-deoxycytidine) and increase of RNA adenine and cytosine methylations (N(6)-methyladenosine and 5-methylcytidine) in CTCs compared with whole blood cells. The discovery of DNA hypomethylation and RNA hypermethylation in CTCs in the current study together with previous reports of global DNA hypomethylation in tumor tissues suggest that nucleic acid modifications play important roles in the formation and development of cancer cells. This work constitutes the first step for the investigation of DNA and RNA methylation in CTCs, which may facilitate uncovering the metastasis mechanism of cancers in the future.


Asunto(s)
Metilación de ADN , ADN de Neoplasias/análisis , ADN de Neoplasias/química , Neoplasias Pulmonares/química , Células Neoplásicas Circulantes/química , ARN Neoplásico/análisis , ARN Neoplásico/química , Cromatografía Líquida de Alta Presión , ADN de Neoplasias/sangre , Humanos , Neoplasias Pulmonares/sangre , Neoplasias Pulmonares/patología , Células MCF-7 , Células Neoplásicas Circulantes/patología , ARN Neoplásico/sangre , Espectrometría de Masas en Tándem
19.
Artículo en Inglés | MEDLINE | ID: mdl-25939097

RESUMEN

An ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) method was developed to determine liensinine in rat plasma using carbamazepine as the internal standard (IS). Sample preparation was accomplished through a protein precipitation procedure with acetonitrile to 0.1ml plasma sample. The analyte and IS were separated on an Acquity UPLC BEH C18 column (2.1mm×50mm, 1.7µm) with the mobile phase of acetonitrile and 0.1% formic acid in water with gradient elution at a flow rate of 0.40ml/min. The injection volume was 6µl. The detection was performed on a triple quadrupole tandem mass spectrometer equipped with electrospray ionization (ESI) by multiple reactions monitoring (MRM) of the transitions at m/z 611.6→206.2 for liensinine and m/z 237.1→194.2 for IS. The linearity of this method was found to be within the concentration range of 10-1000ng/ml with a lower limit of quantification of 10ng/ml. Only 3.0min was needed for an analytical run. The matrix effect was 93.8-107.4% for liensinine. The intra- and inter-day precision (RSD %) were less than 9.9% and accuracy (RE %) was within ±10.5%. The recovery ranged from 76.2 to 86.8%. Liensinine was sufficiently stable under all relevant analytical conditions. The method was also successfully applied to the pharmacokinetic study of liensinine in rats. The pharmacokinetic parameters were demonstrated as followed: t1/2 was 8.2±3.3h, Cmax was 668.4±156.9ng/ml, and AUC0→∞ was 1802.9±466.4ng/mlh.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Isoquinolinas/sangre , Fenoles/sangre , Espectrometría de Masas en Tándem/métodos , Animales , Estabilidad de Medicamentos , Isoquinolinas/química , Isoquinolinas/farmacocinética , Límite de Detección , Modelos Lineales , Masculino , Fenoles/química , Fenoles/farmacocinética , Ratas , Ratas Sprague-Dawley , Reproducibilidad de los Resultados
20.
ACS Appl Mater Interfaces ; 7(16): 8817-26, 2015 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-25853336

RESUMEN

Isolation of rare, pure, and viable circulating tumor cells (CTCs) provides a significant insight in early cancer diagnosis, and release of captured CTCs without damage for ex vivo culture may offer an opportunity for personalized cancer therapy. In this work, we described a biotin-triggered decomposable immunomagnetic system, in which peptide-tagged antibody designed by chemical conjugation was specifically immobilized on engineered protein-coated magnetic beads. The interaction between peptide and engineered protein can be reversibly destroyed by biotin treatment, making capture and release of CTCs possible. Furthermore, the peptide could mediate multiple antibodies' coimmobilization on engineered protein-coated magnetic beads, by which capture efficiency for CTCs was obviously improved. Quantitative results showed that 70% of captured cells could be released by biotin addition, and 85% of released cells remained viable. In addition, 79% of cancer cells spiked in human whole blood were captured and could also be successfully released for culture. Finally, immunomagnetic beads simultaneously loaded with anti-EpCAM, anti-HER2, and anti-EGFR were successfully applied to isolate and detect CTCs in 17 cancer patients' peripheral blood samples, and 2-215 CTCs were identified with high purity. These results suggest that our method is reliable and has great potential in CTC detection for CTC-based molecular profiling, diagnosis, and therapy.


Asunto(s)
Biotina/química , Separación Inmunomagnética/métodos , Microesferas , Células Neoplásicas Circulantes/patología , Antígenos de Neoplasias/metabolismo , Moléculas de Adhesión Celular/metabolismo , Línea Celular Tumoral , Separación Celular , Supervivencia Celular , Molécula de Adhesión Celular Epitelial , Humanos , Inmunoglobulina G/metabolismo , Estreptavidina/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...